When I bought my car a few months ago it had new brakes put on it. Now when I hit the brakes they squeak really bad and the car shakes when braking from 15-0mph. This noise is coming from the back left wheel and it also makes a squeak when I turn right. Also sometimes it seems like the car is teeter tottering when I have it in D and my foot off the gas just coasting very slow. I had the wheel off and the brakes look perfectly fine. Any idea what this could be?

99 Z28 A4